           play-btn     (button :text "play")
           bpm-spinner  (spinner :model (spinner-model (metro :bpm) :from 20 :to 300 :by 1)
                                 :maximum-size [60 :by 100])
-          step-lbls    (vec (for [i (range steps)] (label :size [25 :by 25] 
+          step-lbls    (vec (for [i (range steps)] (label :size [25 :by 25]
                                                           :background "#22F"
                                                           :opaque? false
                                                           :border (line-border :color "#22A"))))
-          control-pane (toolbar :floatable? false 
+          control-pane (toolbar :floatable? false
                                 :items [play-btn
                                         :separator
-                                        bpm-spinner 
+                                        bpm-spinner
                                         [:fill-h 5]
                                         "bpm"])
           seq-pane     (mig-panel :constraints [(str "wrap " (inc steps)) "" ""]

  (use 'overtone.live)
  (use 'overtone.gui.sequencer)
  (use 'overtone.gui.control)
  (use 'overtone.inst.synth)
  (def m (metronome 128))
  (step-sequencer m 8 ks1 ping)
)

                   (repaint! step-lbls)))
      (listen play-btn :action
              (fn [e]
                (let [playing? (:playing? (swap! state-atom toggle-playing))]
                  (config! play-btn :text (if playing? "stop" "play"))
                  (if playing?
                    (step-player state-atom (metro) steps instruments)))))
